Transmission gear lock



Nov. 8, T927.

1,648,754 F. D. CARPENTER TRANSMISSION GEAR Loox Filed July 15. 1926 2 sheets-sheet 1 F. D. CARPENTER TRANSMISSION GEAR LOCK Nov. s, 1927. 1,648,754

Filed July 13. 1925 2 Sheets-Sheet 2 27am/QZ. kapen Patented Nov. 8, 1927.

herren .STATES FRANK D. CARPENTER, LOF 'CGl'CO'oiL MESNE ASSGllMENTS, TO TEE GATMS w :t-reivrrsnrnn, sesiones, BY :oi-nner AND TRASMSSON GEAR LOCK.

Application filed July 2.3,

This invention relates 4to transmission gear-locks for auto vehicles andlhas for lits principal object the provision of means for locking the gears against rotation, and in neutral position, so that the vel icle may not he moved in a forward direction.

in known types of transmission locks the Vgear shaft leverfal'one is locked in neutro-.l position, lhut this does not prevent turning `of the gears when it is attempted to move the vehicle by extraneous force, and a vehicle so locked maybe towed away without impediment. The present invention provides means making `it in'ipossihle either to rotate the shaft upon which the sliding gears are mounted or to shift any of the sliding gears to a position in which they may actively engage .one of the engineedriven .gears when one .of the gears is looked'.

Another object of the invention is ,the vision.y in a gear loc-k of the classde of means whereby the lock yields when the vehicle is moved rearwardly. This feature is essential in order to comply with certain town ordinanceswhich require that a vehicle must. he so locked as to he free ,to :he moved in case of emergency, and at the same time it affords no opportunity for annnauthoilsed Yper-so-n to tow the car away, since it isv not practical to tow aear backwards on account of the inability to :make the front or-steering wheels track with the rear wheels.

Still another object of the invention is 'to provide a transmission geardock which au tomatically moves to locking position npon release of a catch, the use ,of a key heing nocessary only to unloelrthe mechanism.

Still another ohjeetof the invention is the provision of a transmission gear-loch, which hy unimportant changes in the six/.e or proportions of certain of its part-s, may lie adapt-ed for use with any of the desigusof i transmission mechanism now in use, without departing from the principles of the invention.

Other object-s of the invention will appear as the following description. of an illustrative embodiment thereof proceeds.

In the drawings Y Fig. l is a transvrse section through a transmission gear-lock constructed according vto the .principles of thepresent invention, showing the gearlock in operntiif'e relation yto the gear case andthe gears.

' gine shaft l.

1926. Serial N0. 122,238.

Figure 2 is a similar view, parts being broken away showing the gear-lock .in position of release.

Valong/the line 8-.8 .of Figure 6.-

Referring now in detail to the several iigures, and first adverting :tothe ei'iumeration of parts which are old and well known inthe selective type transmission mechanism having three speeds forward and one reverse, the reference immoral 5 .represents a gear which is permanently and slidahly connected ,tothe clutch shaft .l driven hy the engine,

the clutch mechanism not being shown. Reference numeral 2 represents the main gear set shaft that drives the rear wheels of the auto vehicle. notes a lay shaft or-countershaft which vcarries a gear vnot sho vn, constantly in mesh with the gear 50u theengine driven shaft l. lt therefore follows that the lay shaft B constantly driven through the engine driven shaft l so longas the clutch mechanism is in engagement. li/ lounted n mrotatably, hut independently slidalole upoirtlie shaft 2 are sliding gears 5, 6 and 7.v 'flieg-ears 4f and 5 have elements on their adjacent faces which are brought together when the gear 5 slid into contact with the gear i so that the shaft 2 is then directly driven t-hronghthe enof high gear or third. speed forward transmission. The gears 6 and 7 may he slid into operative engagement with certain gears, not shown, Lon the lay shaft representing the low and intermediate gear .ratio respectively. Itis apparent that hy rlocking eitherV ofthe sliding gears 6er 7 against rotation the shaft@ will he locked against rotation and the rearvv'heels of the vehicle cannot turmy hut it is also important thatthe gear 5 he The reference numeral de-y This represents the position lee ria-I restrained trom going into engagement with the gear Il, and that the gears 6 and 7 be kept from meshing With the engine driven gears on the lay shaft, ior should it be possible to place an)7 ot these sliding gears into driven relation while shaft 2 is locked against rotation, breakage ot some part would be almost certain to occur. Since the sliding gears 5, G and l are non-rotatably mount-ed, that is to say, splina-bly mounted upon the shaft 2 it is only necessary to lock one of these gears upon shatt 2 against rotation to keep the sliait and other gears trom rotating. Since the gears 5, G and 7 are iu dependently slidable, it is necessary to provide means tor holding each oi them in neutral position While any one et them is locked, in order safely and practically to accomplish the purpose ot' the present invention.

jitter due investigation l have found that in practically all transmission mechanisms a gear-lock may be applied with most convenience to the second or interniediate sliding gear, there being more room in thetransmission case at this point tor the location of a gear-lock than in any other part ot the transmission casing. Therefore, in illustrating my invention ttor the purpose ot this application l have shown the gearlock in operative position vadjacent the, intermediate gear, although it is Well within the spirit o'l the invention to apply it to any ot the other sliding gears, could this be done adfantageously. A

The transmission lock consists ot three main members, a trame 8 having a flanged end 9 adapted to be secured to the .inner side Wall ot the transmission casing l0, a carriage r11 telescopically arranged in the end orp the trame 8 which Alaces the intermediate gear, and a keeper 12 telescopically positioned in suitably shaped recess in the carriage. In the present embodiment l have shown the trame, carriage, and keeper as being rectangular in cross section, and the recesses in which they telescope ot correspond 'ing shape, but there is nothing in the con-- templation oit the invention to impose this shape as a limitation upon any form which the invention may legitimately take. A spring 1 3 oit' rather heavy tension occupies the recess Within the iframe 8 and presses against the carriage 11, urging it outwardly, that is to toward theintermediate gear. another spring 11i, preferably ot lighter tension, lies in the recess Within the carriagell and presses against the keeper 12 urging it normally outwardly towardthe gears. 'lhe keeper l2 is provided with teeth le adapted to mesh with the teeth on the intermediate gear. `Normally the foremost ot the teeth lll merely collides with the side ot one oit the teeth ot the intermediate gear as isindicated in Figure 3 holding the device in readiness to be inevitably locked with the gear sliould it be attempted to move the auto vehicle forward While the keeper 12 is in this position. The keeper is limited in its 'out-- Ward movement by an upturned edge 15, or equivalent means formed on a bed plate 16 which is riveted or other vise suitably secured tothe carriage l1 so as to be a unitary part thereof. rl`he bed plate is preferably termed With lateral grooves 17 into Which the flanges 1.8 termed on the sides ot the keeper extend, so ythat the bed plate acts as a guideway for the keeper, retaining it against displacenicnt.

rl"he :trame 8 is provided with an upright extension 19 projecting through a suitably lormed oijiening inthe top oil: the gear casing. This extension, as ivill be observed trom F i gures l and 5, is provided With three bores extending longitudinally .through it 'from top to bottom.

character 2O is provided with a plunger A2l normally pressed resiliently downward by a spring 22 abutting at one end against a collar 23 formed on said plunger and at the other against a. suitable abutment constituted by a bushing 24. rlhe lower end ot the plunger normally bears againsty the top face of the carriage 11 and, when the carriage is retractedvby suitable means, presently to be described, against the tension oi' the spring 13, the plunger linally drops into a Well 25 formed in the carriage, holding thecarriage in retracted position until the plunger is pulled out. It will be noted that there is no positive means for retracting the keeper 12, so that the latter remains in extended position when the carriage is returned. Upon Withdrawal ot the plunger 21 from the Well 25the carriage 11 moves forwardly under the urge ot the spring 13 and projects the keeper 12 into contact with the teeth ofthe intermediate gear, which gear is presumed to be stationary atfthe time. At the same time, the bottom tace ot the bed' plato l5 linds a seat upon the'lay shaft 3 or some structure associated therewith, such as the Vbearing 26, which ailiords a support tor the` bed plate and keeper so that the latter cannot be distorted from its proper position ot alinement with the gear teeth by -forcible yattempt to move the auto vehicle 'forwardly While the gear-lock is in locked position. The bottom tace of the bed'plate 16 is preterably formed on an inclined plane as shown at 27 so that it will ride upon the bearing 26 Without colliding with thesame, and the inclined plane is designed to form an abrupt shoulder 28 Which engages With-the bearing when the keeper is in fully locked position and acts as a stop to prevent jamming ot the keeper between the intern'iediate 'gear' and the bearing` 26. Sait abrupt shoulder functions also to' prevent thecarriage 11 from moving out too far, should the plungerbe @ne ot these bores,A Vnan'iely the one designated by the reference lll() inadvertently withdrawn when the interme' diate is not in neutral position and therefore not in the way to interengage the locking mechanism.

The carriage 11 is yprovided on its top face witha slot 29 having teeth 30 along one side thereof. The vertical extension 19 is provided in one of its bores with a shaft 31 having a pinion 32 at its Vvlower end housed in the slot 29 and engaging the teeth 30. The upper end of the shaft 31 is provided with any suitable means for retainingit within the extension 19 such as a collar 33 against which a bushing 341 abuts, holding the shaft 31 in place. A foot pedal 35 is suitably secured to the outer end ofthe shaft 31. lVhen the foot pedal is pressed the shaft 31 rotates, as does the pinion 32 at its lower end, the latter meshing with the teeth 30 and ret-meting the carriage. The tension of the spring' 13 is suflicient to overcome the inertia andthe friction of all parts associated with the shaft 31 so that when the spring expands upon release of the plunger 21V the shaft 31 and parts carried thereby are automatically rotated to the position assuined when the carriage 1s in extended po- 'sition The'third 'bore of the extension 19 contains a lock 36 having a normally extended detent 37'adapted to travel in a slot/38 formedY in the upper face of the carriage and to cooperate with a resiliontly mounted catch 39 borne by'said carriage. Said catch has a cam face 40 on the side adjacent the intermediate fear 7 and an abru at face 41 on the on aosite side. The catch is housed in a recess? 42 formed in theupper wall ofthe carriage and is normally pressed outwardly by a spring 43'housed in said recess. When the plunger 21 is withdrawn andthe carriage is moved Vby the spring; 13 toward the ge rs,the catch 39 rides over the cam face 3T of thedetent, (ilepressing-the latter below thefplane of the 'upper end ofthe slot 33, andwhen'the catch passes said detent 39 the latter springs up under the urge ofthe springl t3 confrontingr the abrupt face 41 of said detent so that the carriage cannot move backwardsiwhile the catch is in the way tent thus afford a positive ineansfor locking rthe gear-lock in its gear-engaging. position, .V c, L). n b

and thelock 36 is preferably of such characteras to cause the withdrawal of the detent `upon vthe insertion ofy a keyintosaid lock,

permitting the release of the carriage. The lock 36 per se forms no part of my invention, since such locksare wellV known.

When it is desiredto look thegears, vthe auto vehicle having first .been brought to va standstill, it is merely necessary i'irst't'o put the gear 7 in neutral andV pull outthe plunger 21 whereupon :the lcarriage 11 Vwill be moved by the spring 13 toward the gear, carrying with it thekeeper 12, vthe latter bethe auto vehicle be tampered with., but it The catch and deing in normally extended position, until the foremost tooth of the keeper' strikes the teeth of the intermediate gear. The advancing movement of the carriage will 'be limited by the abutment of the shoulder 23 against `the bearing 2G. while the keeper itself will be pushedr back by the gear teeth against the tension of the s aringrlt to the position shown in Figure 3, in readiness to go into mesh with the teeth of the intermediate gear should the auto vehicle be moved forwardly. The spring 1d acts as a shock absorber to relieve the impact of the keeper against the gear teeth. When the carriage assumes the gear-locking position, the catch 39 passes behind the detent 37 and prevents the release of the gear-lock. hen the operator wishes to unlock the gears he places the key in the lock 36withdrawing the detent 37'. He then presses upon the foot pedal 35, and normally,

if the auto vehicle has not been disturbed in l so as to be interlocked therewith as shown in Figure 1 so that retraction of the keeper may not be effected by pressure upon the pedal alone. In this case it is necessary for the operator to push the car a short distance in a reverse direction in order to rotate the intermediate gear 7 reversely and thereby retract the keeper 12 out of mesh with said gear. After this, pressure upon ythe pedal will restore *the carriage to its normal inactive position in which the plunger 21 enters the wellv 25. The spring 11- between thecarriage and'keeper not only permits the auto vehicle to be pushed backwards for the purpose of'releasing` the keeper from the inten mediate gear in the manner aforesaid, should also enables the auto vehicle to be pushed any Lkdistance in a reverse direction should it be necessary to move it while parked in case of emergency such as, for instance., to make vroom for the fire department.

It would be an easy matter to break the gear lock or .the intermediate gear 7. were the other sliding gears left free to be con- This nected to the engine drive shaft.

:eventedby an arm .4r-5 securedr to the caron and fingers 119 Aand 5() which straddle itermediate gear'T when it is in neutral position and a single Enger ,4L-8 adapted to preventthe'intermeshment ofr the high gearv withthe engine driven 'ear'5. dlienthe moves -to locking position these fingersare introduced into the path of longitudinal movement of said gears prevent lou liz:

` path ot movement ot said gear,

ing the shifting thereot While the locking device is in gear locking position. -When the carriage is returned to release position said fingers are Withdrawn from the path oit longitudinal movement of said gears.

Nliil I have in. the above description disclosed what l believe to be a preferred and practical embodiment of my invention, it to be understood that the specific details described are not limitative in their'etlect upon the invention but merely illustrative except in so tar as they are expressly prescribed by the terms ot the appended claims.

Having described niy invention What ll claim as new and desire to secure by LettcrsPatcnt, is

1. ln combination, agear and means tor locking said gear against rotation in one direction comprising a carriage, a gear-engaging member movable with said carriage and relatively thereto, means normally biasing said gear-engaging member in a direction toivard said gear, means 'for advancing said carriage to bring said gear-engaging member into the path of movement of said gear,

entrained in the teeth of said gear upon rotation oiE the latter in said direction, and

ineans for limiting the movement of said gear-engaging member in said-direction, said member being retractable relatively to said carriageV against said biasing means upon engagement With said gear or upon movenicntof said gear in the reverse direction.

'2. ln combination a gear and means for locking said gear against rotation in one direction comprising a carriage, a gear-en-V gaging member movable With said carriage and relatively thereto, means normally biasing said gear-engagingmember relatively to said carriage in a direction toward said gear, 'means ttor advancing said carriage to lbring said gear-eneaging ineinber into the said member being const rncted to be entrained in the teeth ot said gear upon rotation oit the latter in said direction, means 'lfor limiting the nieveiiient et said gear-engaging inoi'nber iii said direction, said nien'iber beingV retractable relatively to said carriage against said biasing means upon engagement with said gear or upon movement ot said gear in reverse direction, means for locking said carriage Vin advanced position, a housing tor said carriage, rotatable means for withdrawing said carriage Within rsaid housing from the path or said gear when said lockingineans is iinlocked, and resilient means for resistingivithdraival o't said carriage into said housing latching said carriage in retracted position.

In combination a gear and means for locking said gear against rotation in one direct-ion comprising a carriage, a gear-engaging member movable with said carriage and relatively thereto, means normally biassaid member being constructed to beA ing said gear-engaging member in a direction toward said gear, means 'for advancing said carriage for bringing said gear-engaging member into the path of movement oi' said gear, said member being constructed to be entrained in the path of said gearupon rotation ot the latter in said direction, means for limiting the movement of saidy gear-engaging member in said direction, said meinber being retractable relatively to said carriage againstsaid biasing means upon engagement with said gear or upon movement ot said gear in reverse direction, means for locking said carriage in advanced position, means comprising a lfoot operated pinion engageable with a rack on said carriage rtor withdrawing said carriage with said gearengaging member from the path of said gear, when lsaid locking means is unlocked and a. releasable latch ltor holding said carriage in retracted position.

il. ln combination, a gear and means for locking said gear against rotation in one direction, comprising a trame adapted to be iixcdly supported, a carriage carried by lsaid iframe and movable relatively thereto, a gear-engaging member movable Within said carriage and relatively thereto, means .normally biasing said gear-engaging member in direction toward said gear, mea-ns between said trame and carriage for normally biasing the latterv in a direction and toV van eX- tent to bring said gear-.engaging member into the path of movement of `said gear, said member being constructed to be en* trained in the path ofv said gear upon rotation of the latter in saiddirection, meansl tor limiting the movement of said gear-engaging member in said direction, said member being retractable relatively to said carriage upon engagement With said `*gear or upon movement of said gear in reverse direction, means for locking said carriage in advanced position, means for withdrawing said carriage with said gear-engaging meinber ifrom the lpath of said gear When said locking means is unlocked, and a releasable hitch tor holding said carriage in retracted position.

ln combination, a shaft, sliding gears on said shaft each having a neutral position and being independently engageable with speed changing mechanism, means cooperating ivith one ot said gears While it is in neutral position-tor locking said gear against rotation in one direction comprising means movable toivard and away from said gear, means movable relatively to saidiirst-named means and projectable into theY path ot movement of said gear and adaptedv tofbe entrained in the teeth of said gear upon rotation orq the latter in said direction, means 1in Y associated with said first-named means for v limiting the lmovement of said projectable means in said'direction, andmeans movable neutral position for locking one oit said` gears against rotation in one direction comprising` a carriage having a gear-engaging member, means for advancing said carriage to bring said gear-engaging member into the path ot movement oit said gear, said member being Constructed to be entrained in the -teeth of ysaid gear upon rotation of the latter in said direction, means for limiting the movement ol said gear-engaging member in said direction, and means carried by said carriage :tor maintaining said other gears in neutral position While the one gear is locked against rotation.

7. In combination, a gear case, parallel shafts Within said gear case, a gear on one shaft, means for locking said gear against rotation in one direction comprising a tram-e adapted to be iiXedly supported Within said gear case, a carriage carried by said frame and movable relatively thereto, a gear-engaging member movable with said carriage and relatively thereto, means for normally biasing said gear-engaging member in a direction toward said gear, means between said trame and carriageffor normally biasing the latter in a direction and t0 an extent to bring said gear-engaging member into the path ot movement of said gear, said carriage, When in advanced position, being supported by structure associated Witih said, other shaft, said gear-engaging member being constructed to be entrained in the teeth of said gear upon rotation o'l' the latter in said direction, and means :tor limiting the movement oit said gear-engaging member in said direction, said gear-engaging member being retractable relatively to said carriage upon engagement with said gear or upon movement ot said gear in reverse direction.

8. In combination, a gear case, parallel shafts within said gear case, a gear on one :'51

sliait, means for locking saic gear in one direction comprising a trame adapted to be iXedlysupport-ed Within said gear case, a carriage carried by said frame and movable relatively thereto, a gear-engaging member movable with said carriage and relatively thereto, means normally biasing said gearengaging member in a direction toward said gear, means between said trame and carriage for normally biasing the latter in a .direction and to an extent to bring said gearengaging member into the path of movement of said gear, said carriage being supported when in advanced position by structure associated with said other shaft, said carriage being formed with means co-acting With said structure to limit the movement of said carriage in said direction, said gear-engaging member being constructed to be entrained in the teeth of said gear upon the rotation of the latter in said direction, and means for limiting the movement of said gear-engaging member in said direction, said gearengaging member being retractable relatively to said carriage upon engagement With said gear or upon movement ot said gear in a reverse direct-ion.

In testimony whereof I have hereunto set my hand.

FRANK D. CARPENTER. 

